A glowing metal ring crashed to the ground. No one knows where it came from

It’s been more than a week since reports first emerged of a “glowing metal ring” that fell from the sky and crashed near a remote village in Kenya.

According to the Kenya Space Agency, the object weighed 1,100 pounds and was more than 8 feet in diameter when measured after landing on December 30. Two days later, the space agency confidently stated that the object was a piece of space debris. Saying that it was a ring that separated from the missile. “Such objects are usually designed to burn up upon re-entry into Earth’s atmosphere or to fall over uninhabited areas, such as oceans,” the space agency said. He told the New York Times.

Since these initial reports were published in Western media, a small group of space trackers have used open source data to try to accurately identify the space object that crashed into Kenya. They have not yet been able to determine the source of the missile launch to which the large ring can be attributed.

Now, some space trackers believe the object may not have come from space at all.

Did he really come from space?

Space is increasingly crowded, but large pieces of metal from rockets generally do not fly into Earth’s orbit undetected or tracked.

“It has been suggested that the ring is space debris, but the evidence is marginal.” books Jonathan McDowell is an astrophysicist at the Harvard-Smithsonian Center for Astrophysics. McDowell is highly regarded for his analysis of space objects. “The most likely space-related possibility is the re-entry of the SYLDA transformer from Ariane V184 flight, object 33155. However, I am not entirely convinced that the ring is space debris at all,” he wrote.

Marco Langbroek, another prominent space tracker, believed it was plausible that the ring came from space, so he further investigated objects that may have returned around the time the object was discovered in Kenya. in Post written on Wednesday He noted that apart from the metal ring, other fragments that appear consistent with space debris — including carbon shell-like materials and insulation foil — have been found several kilometers away from the ring.

Like McDowell, Langbroek concluded that the most likely source of this object was… Ariane V launch It happened in July 2008, when the European rocket launched two satellites into geosynchronous transfer orbit.

The Ariane V rocket was a somewhat unique rocket in that it was designed with the ability to launch two medium-sized satellites into geostationary transfer orbit, a much more popular destination in the late 1990s and early 2000s than it is today. To accommodate both satellites, a SYstème de Lancement Double Ariane (SYLDA) shell was placed above the lower satellite to support the installation of a second satellite above it. During a launch in 2008, this SYLDA shell was ejected into a geosynchronous transfer orbit at a 1.6-degree angle, Langbroek said.

Could it have come from a European missile?

Over the years, this object has been tracked by the US military, which maintains a database of space objects so that active spacecraft can avoid collisions. Since there are no tracking stations near the equator, this object is observed only periodically. According to Langbroek, its last observation was made on December 23, when it was in a highly elliptical orbit, reaching perigee just 90 miles (146 km) from Earth. This was a week before an object crashed in Kenya.

Based on his model of SYLDA return probability, Langbroek believes it is possible that the European object may have landed in Kenya at around the time its entry was observed.

However, an anonymous X account using the name DutchSpace, which despite its anonymity has provided reliable information about Ariane launch vehicles in the past, Posted a topic This indicates that this loop cannot be part of the SYLDA shell. From the photos and documents, it is clear that the diameter or mass of the SYLDA component does not match the ring in Kenya.

In addition, Arianespace officials He told Le Parisien newspaper on Thursday that they did not believe the space debris was related to the Ariane V rocket. Basically, if the ring doesn’t fit, you have to acquit.

So what was it?

This story originally appeared on Ars Technica.